Pyrolytic Graphite is a unique form of graphite manufactured by decomposition of a hydrocarbon gas at very high temperature in a vacuum furnace&period; The result is an ultra-pure product which is near theoretical density and extremely anisotropic&period; The material is grown onto a substrate giving it a layered composition&period; This also means it has different properties in different planes&period; In the C plane &lpar;across its layers&rpar; it has low thermal conductivity&comma; acting as an insulator&period; In the A-B plane &lpar;with the layers&rpar; it has very high thermal conductivity&comma; acting as a superb conductor&period;